syzbot


uvm_fault: mld6_fasttimeo

Status: upstream: reported on 2025/04/22 01:42
Reported-by: syzbot+b843219f5b8e26c241c2@syzkaller.appspotmail.com
First crash: 16d, last: 16d

Sample crash report:
uvm_fault(0xffffffff8387c790, 0x1, 0, 1) -> e
kernel: page fault trap, code=0
Stopped at      mld6_fasttimeo+0x133:   movzbl  0x1(%rax),%r15d
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*301101   6812      0     0x14000 0x40000200    0  softclock
mld6_fasttimeo() at mld6_fasttimeo+0x133 mld6_checktimer sys/netinet6/mld6.c:383 [inline]
mld6_fasttimeo() at mld6_fasttimeo+0x133 sys/netinet6/mld6.c:363
pffasttimo(ffffffff83977ad0) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83977ad0) at timeout_run+0xc0 sys/kern/kern_timeout.c:-1
softclock_thread(ffff80002a72d710) at softclock_thread+0xe3 sys/kern/kern_timeout.c:810
end trace frame: 0x0, count: 11
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports.  Insufficient info makes it difficult to find and fix bugs.
ddb> 
ddb> set $lines = 0
ddb> set $maxwidth = 0
ddb> show panic
*cpu0: uvm_fault(0xffffffff8387c790, 0x1, 0, 1) -> e
ddb> trace
mld6_fasttimeo() at mld6_fasttimeo+0x133 mld6_checktimer sys/netinet6/mld6.c:383 [inline]
mld6_fasttimeo() at mld6_fasttimeo+0x133 sys/netinet6/mld6.c:363
pffasttimo(ffffffff83977ad0) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83977ad0) at timeout_run+0xc0 sys/kern/kern_timeout.c:-1
softclock_thread(ffff80002a72d710) at softclock_thread+0xe3 sys/kern/kern_timeout.c:810
end trace frame: 0x0, count: -4
ddb> show registers
rdi                              0x2
rsi                                0
rbp               0xffff80002a7391c0
rbx                                0
rdx                                0
rcx                              0x1
rax                                0
r8                              0x21
r9                                 0
r10               0xbe4fd44ab1c1462b
r11               0x8f143438ec5a98a3
r12                              0x1
r13               0xffff800001467000
r14               0xffff80000149a800
r15                                0
rip               0xffffffff81f1a8d3    mld6_fasttimeo+0x133
cs                               0x8
rflags                       0x10286    __ALIGN_SIZE+0xf286
rsp               0xffff80002a739190
ss                                 0
mld6_fasttimeo+0x133:   movzbl  0x1(%rax),%r15d
ddb> show proc
PROC (softclock) tid=301101 pid=6812 tcnt=1 stat=onproc
    flags process=14000<NOZOMBIE,SYSTEM> proc=40000200<SYSTEM,CPUPEG>
    runpri=0, usrpri=51, slppri=0, nice=20
    wchan=0x0, wmesg=, ps_single=0x0 scnt=0 ecnt=0
    forw=0xffffffffffffffff, list=0xffff80002a72d9a0,0xffff80002a72d490
    process=0xffff8000ffffda10 user=0xffff80002a734000, vmspace=0xffffffff8387c790
    estcpu=1, cpticks=1, pctcpu=0.0, user=0, sys=2, intr=0
ddb> ps
   PID     TID   PPID    UID  S       FLAGS  WAIT          COMMAND
 99670   72818  67370      0  2           0                syz-executor
 99670  506867  67370      0  2   0x4000000                syz-executor
 86823  181818  83526      0  2           0                syz-executor
 86823  117169  83526      0  3   0x4000080  fsleep        syz-executor
 46819  371808  18638      0  2           0                syz-executor
 46819  311361  18638      0  3   0x4000080  fsleep        syz-executor
 46819  326353  18638      0  3   0x4000080  fsleep        syz-executor
 92024  152457  44396      0  2           0                syz-executor
 92024  407330  44396      0  3   0x4000080  fsleep        syz-executor
 92024  407328  44396      0  3   0x4000080  fsleep        syz-executor
 49311  360660  21616      0  2        0x10                syz-executor
 49311  461392  21616      0  3   0x4000090  fsleep        syz-executor
 49311  418061  21616      0  3   0x4000090  fsleep        syz-executor
 34464  291860  19506      0  2           0                syz-executor
 34464    9248  19506      0  3   0x4000080  fsleep        syz-executor
 34464  202871  19506      0  3   0x4000080  fsleep        syz-executor
 20201  138240  39592  60928  2        0x10                syz-executor
 20201  181982  39592  60928  2   0x4000010                syz-executor
 20201  288916  39592  60928  3   0x4000090  fsleep        syz-executor
 20201   93656  39592  60928  3   0x4000090  fsleep        syz-executor
 18638  327226  79432      0  3        0x82  nanoslp       syz-executor
 11174   34459      0      0  3     0x14200  acct          acct
  9097  353821      0      0  3     0x14200  bored         sosplice
 44396  106383  79432      0  2       0x482                syz-executor
 83518    5426  79432      0  2       0x482                syz-executor
 39592   46467  79432      0  3        0x82  nanoslp       syz-executor
 21616   68442  79432      0  2       0x482                syz-executor
 19506  147527  79432      0  2       0x482                syz-executor
 83526  504033  79432      0  3        0x82  nanoslp       syz-executor
 67370  382766  79432      0  3        0x82  nanoslp       syz-executor
 79432  245536  16544      0  3        0x82  kqread        syz-executor
 16544  447947  56191      0  3    0x10008a  sigsusp       ksh
 56191  396757  54897      0  3        0x98  kqread        sshd-session
 54897  300220  73226      0  3        0x92  kqread        sshd-session
 99726  418097      1      0  3    0x100083  ttyin         getty
 73226  434488      1      0  3        0x88  kqread        sshd
 82091  123458  91752     73  3   0x1100090  kqread        syslogd
 91752  337205      1      0  3    0x100082  sbwait        syslogd
 13441  341021      1      0  3    0x100080  kqread        resolvd
  3822  199342  98478     77  3    0x100092  kqread        dhcpleased
  8218   57666  98478     77  3    0x100092  kqread        dhcpleased
 98478  141968      1      0  3        0x80  kqread        dhcpleased
 86925  449799      0      0  3     0x14200  bored         smr
 28243   88602      0      0  2     0x14200                zerothread
 34555  373621      0      0  3     0x14200  aiodoned      aiodoned
 23950   18987      0      0  3     0x14200  syncer        update
 61404  324367      0      0  3     0x14200  cleaner       cleaner
 84311  154378      0      0  3     0x14200  reaper        reaper
  9717  372939      0      0  3     0x14200  pgdaemon      pagedaemon
 49727  297325      0      0  3     0x14200  bored         viomb
 83987  238617      0      0  3  0x40014200  acpi0         acpi0
  5037   38913      0      0  3     0x14200  bored         softnet3
 44955   56572      0      0  3     0x14200  bored         softnet2
 27524  141745      0      0  3     0x14200  bored         softnet1
  2703  367967      0      0  3     0x14200  bored         softnet0
 57461   41199      0      0  3     0x14200  bored         systqmp
 48802  355485      0      0  3     0x14200  bored         systq
* 6812  301101      0      0  7  0x40014200                softclock
 68461  511077      0      0  3  0x40014200                idle0
     1  287037      0      0  3        0x82  wait          init
     0       0     -1      0  3     0x10200  scheduler     swapper
ddb> show all locks
No such command
ddb> show malloc
           Type InUse  MemUse  HighUse   Limit  Requests Type Lim
         devbuf 10206  11129K   11690K 166960K     12063        0
            pcb    20     14K      16K 166960K       160        0
         rtable   249     11K      12K 166960K       469        0
             pf    34     13K      18K 166960K       117        0
         ifaddr    41      7K       8K 166960K        69        0
        ifgroup    50      2K       2K 166960K       103        0
         sysctl     4      1K       1K 166960K         4        0
       counters    30     17K      17K 166960K        57        0
       ioctlops     0      0K       4K 166960K       124        0
            iov     0      0K      16K 166960K        38        0
          mount     1      1K       1K 166960K         1        0
            log     0      0K       0K 166960K         4        0
         vnodes  1349     85K      85K 166960K      1935        0
      UFS quota     1     32K      32K 166960K         1        0
      UFS mount     5     36K      36K 166960K         5        0
            shm     3      5K       9K 166960K        12        0
         VM map     2      1K       1K 166960K         2        0
            sem    12     20K      20K 166960K        20        0
        dirhash    12      2K       2K 166960K        24        0
           ACPI  1692    195K     286K 166960K     12470        0
      file desc    18     65K      97K 166960K       686        0
          sigio     0      0K       0K 166960K         6        0
           proc    62     67K     124K 166960K       577        0
        subproc    72      4K       4K 166960K        82        0
    NFS srvsock     1      0K       0K 166960K         1        0
     NFS daemon     1     16K      16K 166960K         1        0
    ip_moptions     0      0K       0K 166960K        82        0
       in_multi    98      7K       7K 166960K       122        0
    ether_multi     1      0K       0K 166960K         4        0
            mrt     0      0K       0K 166960K         8        0
    ISOFS mount     1     32K      32K 166960K         1        0
  MSDOSFS mount     1     16K      16K 166960K         1        0
           ttys   229   1023K    1023K 166960K       229        0
           exec     0      0K       1K 166960K       473        0
   fusefs mount     1     32K      32K 166960K         1        0
            tdb     3      0K       0K 166960K         3        0
        VM swap     8     62K      64K 166960K        10        0
       UVM amap   252    152K     170K 166960K      8000        0
       UVM aobj    16      2K       4K 166960K        18        0
     pinsyscall    39     78K     100K 166960K      1769        0
        memdesc     1      4K       4K 166960K         1        0
    crypto data     1      1K       1K 166960K         1        0
    ip6_options     0      0K       0K 166960K        31        0
            NDP    11      0K       2K 166960K        47        0
           temp    55   8671K    8748K 166960K     25204        0
         kqueue    14     22K      30K 166960K       118        0
      SYN cache     2     16K      16K 166960K         2        0
ddb> show all pools
Name      Size Requests Fail Releases Pgreq Pgrel Npage Hiwat Minpg Maxpg Idle
rtpcb      120      141    0      137     3     2     1     3     0     8    0
rtentry    136      133    0       27     4     0     4     4     0     8    0
unpcb      144      802    0      721     9     1     8     8     0     8    5
syncache   336        8    0        8     2     1     1     1     0     8    1
tcpqe       32        3    0        3     2     1     1     1     0     8    1
tcpcb      808      145    0      139     2     0     2     2     0     8    0
arp         88       22    0        6     1     0     1     1     0     8    0
inpcb      344      731    0      719    15     8     7     7     0     8    5
nd6        104       27    0        3     1     0     1     1     0     8    0
pkpcb       40        5    0        5     2     1     1     1     0     8    1
kcovpl      48        9    0        1     1     0     1     1     0     8    0
mppekey    1024       2    0        2     2     1     1     1     0     8    1
ppxss      1072      21    0       21     3     2     1     1     0     8    1
pppxif     1384       2    0        2     2     1     1     1     0     8    1
pfstscr     40        2    0        2     1     0     1     1     0     8    1
pfrktable  1344       8    0        5     1     0     1     1     0     8    0
pfanchor   1288       6    0        1     1     0     1     1     0     8    0
pftag       88        3    0        1     1     0     1     1     0     8    0
pfstkey    128        4    0        4     1     0     1     1     0     8    1
pfstate    344        2    0        2     1     0     1     1     0     8    1
pfrule     1344      10    0        4     1     0     1     1     0     8    0
rttmr      136        2    0        2     2     1     1     1     0     8    1
art_heap8  4096       2    0        0     2     0     2     2     0     8    0
art_heap4  256      585    0      126    30     1    29    30     0     8    0
art_table   32      587    0      126     4     0     4     4     0     8    0
art_node    16      131    0       36     1     0     1     1     0     8    0
sysvmsgpl   40        5    0        4     1     0     1     1     0     8    0
semupl     112        2    0        2     1     0     1     1     0     8    1
semapl     112       15    0        5     1     0     1     1     0     8    0
shmpl      112       15    0        2     1     0     1     1     0     8    0
dirhash    1024      25    0        8     3     0     3     3     0     8    0
dino2pl    256     2696    0     1192    95     0    95    95     0     8    0
ffsino     248     2696    0     1192    95     0    95    95     0     8    0
nchpl      144     3667    0     1982    63     0    63    63     0     8    0
rtmask      32        6    0        6     1     0     1     1     0     8    1
uvmvnodes   80     2214    0        0    46     0    46    46     0     8    0
vnodes     216     2214    0        0   123     0   123   123     0     8    0
namei      1024   12268    0    12268     3     1     2     2     0     8    2
pfiaddrpl  120        2    0        1     1     0     1     1     0     8    0
kstatmem   264       58    0       36     2     0     2     2     0     8    0
scsiplug    72        3    0        3     1     0     1     1     0     8    1
scxspl     216    10795    0    10795     9     1     8     8     1     8    8
plimitpl   152      148    0      130     1     0     1     1     0     8    0
sigapl     424      971    0      923     7     1     6     7     0     8    0
futexpl     64     8912    0     8901     2     1     1     1     0     8    0
knotepl    120   128269    0   128212    28    18    10    15     0     8    8
kqueuepl   184      233    0      219     2     1     1     2     0     8    0
pipepl     296      176    0      147     5     0     5     5     0     8    2
fdescpl    440      953    0      923     5     1     4     5     0     8    0
filepl     120     6220    0     5926    19     6    13    13     0     8    4
lockfpl    104      278    0      275     1     0     1     1     0     8    0
lockfspl    48       69    0       66     1     0     1     1     0     8    0
sessionpl  144       27    0       19     1     0     1     1     0     8    0
pgrppl      48       41    0       25     1     0     1     1     0     8    0
ucredpl    104     1195    0     1182     1     0     1     1     0     8    0
zombiepl   144     1242    0     1240     2     1     1     1     0     8    0
processpl  1112     971    0      923     4     0     4     4     0     8    0
procpl     656     1959    0     1895     7     1     6     6     0     8    0
sosppl     168        3    0        3     2     1     1     1     0     8    1
sockpl     528     1717    0     1619    26    15    11    16     0     8    4
mcl64k     65536     17    0       17     2     1     1     1     0     8    1
mcl16k     16384      1    0        1     1     0     1     1     0     8    1
mcl9k      9216       3    0        3     2     1     1     1     0     8    1
mcl8k      8192      10    0       10     2     1     1     1     0     8    1
mcl4k      4096    3177    0     3128    15     7     8    14     0     8    1
mcl2k      2048     625    0      624     2     0     2     2     0     8    1
mtagpl      96      109    0       17     3     0     3     3     0     8    0
mbufpl     256     9964    0     9711    18     0    18    18     0     8    1
bufpl      280     3200    0      125   220     0   220   220     0     8    0
anonpl      24   153605    0   147986    49     2    47    47     0   187    3
amapchunkpl 152   26621    0    26000    54    13    41    41     0   158   15
amappl16   200     2450    0     2340    10     0    10    10     0     8    0
amappl15   192       65    0       65     1     1     0     1     0     8    0
amappl14   184      114    0      104     1     0     1     1     0     8    0
amappl13   176        4    0        4     1     1     0     1     0     8    0
amappl12   168     1656    0     1626     3     1     2     3     0     8    0
amappl11   160       79    0       69     1     0     1     1     0     8    0
amappl10   152        5    0        5     1     1     0     1     0     8    0
amappl9    144      255    0      255     1     1     0     1     0     8    0
amappl8    136       39    0       37     1     0     1     1     0     8    0
amappl7    128      104    0       94     1     0     1     1     0     8    0
amappl6    120      182    0      179     1     0     1     1     0     8    0
amappl5    112      116    0      109     1     0     1     1     0     8    0
amappl4    104      323    0      306     1     0     1     1     0     8    0
amappl3     96     5036    0     4912     4     0     4     4     0     8    0
amappl2     88      667    0      609     2     0     2     2     0     8    0
amappl1     80    11526    0    10972    14     0    14    14     0     8    0
amappl      88     7195    0     7008     5     0     5     5     0    92    0
dma4096    4096       1    0        1     1     1     0     1     0     8    0
dma1024    1024       1    0        0     1     0     1     1     0     8    0
dma256     256        6    0        6     1     1     0     1     0     8    0
dma128     128      253    0      253     1     1     0     1     0     8    0
dma64       64        6    0        6     1     1     0     1     0     8    0
dma32       32        7    0        7     1     1     0     1     0     8    0
dma16       16       18    0       17     1     0     1     1     0     8    0
aobjpl      72       17    0        2     1     0     1     1     0     8    0
uaddrrnd    24      953    0      923     1     0     1     1     0     8    0
uaddrbest   32        2    0        0     1     0     1     1     0     8    0
uaddr       24      953    0      923     1     0     1     1     0     8    0
vmmpekpl   168     9652    0     9606     3     0     3     3     0     8    0
vmmpepl    168    67026    0    65008    94     1    93    93     0   357    2
vmsppl     360      952    0      923     4     1     3     4     0     8    0
rwobjpl     32    22040    0    18843    27     0    27    27     0     8    0
pdppl      4096    1912    0     1846   108    42    66    82     0     8    0
pvpl        32   420017    0   409147   137    12   125   125     0   265   18
pmappl     216      952    0      923     3     0     3     3     0     8    0
extentpl    40       45    0       27     1     0     1     1     0     8    0
phpool     112      290    0       57     8     0     8     8     0     8    0
ddb> machine ddbcpu 0
No such command
ddb> trace
mld6_fasttimeo() at mld6_fasttimeo+0x133 mld6_checktimer sys/netinet6/mld6.c:383 [inline]
mld6_fasttimeo() at mld6_fasttimeo+0x133 sys/netinet6/mld6.c:363
pffasttimo(ffffffff83977ad0) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83977ad0) at timeout_run+0xc0 sys/kern/kern_timeout.c:-1
softclock_thread(ffff80002a72d710) at softclock_thread+0xe3 sys/kern/kern_timeout.c:810
end trace frame: 0x0, count: -4
ddb> machine ddbcpu 1
No such command
ddb> trace
mld6_fasttimeo() at mld6_fasttimeo+0x133 mld6_checktimer sys/netinet6/mld6.c:383 [inline]
mld6_fasttimeo() at mld6_fasttimeo+0x133 sys/netinet6/mld6.c:363
pffasttimo(ffffffff83977ad0) at pffasttimo+0x184 sys/kern/uipc_domain.c:-1
timeout_run(ffffffff83977ad0) at timeout_run+0xc0 sys/kern/kern_timeout.c:-1
softclock_thread(ffff80002a72d710) at softclock_thread+0xe3 sys/kern/kern_timeout.c:810
end trace frame: 0x0, count: -4

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/22 01:41 openbsd e8eeea37c7e6 552876f8 .config console log report [disk image] [bsd.gdb] [kernel image] ci-openbsd-main uvm_fault: mld6_fasttimeo
* Struck through repros no longer work on HEAD.